Dear Toolmakers,

They say a carpenter is only as good as his tools, but the same is true for Geometers. Today we will use half-circle and full-circle protractors to measure angles. When we use a tool, we have to know how to use it accurately and precisely. We also have to know how to use it responsibly, because the reverse of that saying is true as well: our tools are only as good as we are.

Just as you always estimate before you calculate, you should also have an idea of what you want to do with your tool before you begin using it. In the case of angles, we should always classify them as acute, obtuse, right, straight, or reflex before we ever line our protractor up with the vertex of the angle.

Speaking of tools–Marshall McLuhan once said, “First we shape our tools, then they shape us.” What do you think that means? How have tools shaped you and how you think about the world?

Sincerely,

Mr. Heimbuck